Option Explicit
 
Declare Function AppendMenu Lib "user32" Alias "AppendMenuA" (ByVal hMenu As _
  Long, ByVal wFlags As Long, ByVal wIDNewItem As Long, ByVal lpNewItem As _
  String) As Long
Declare Function GetSystemMenu Lib "user32" (ByVal hWnd As Long, ByVal bRevert _
As Long) As Long
Declare Function SetWindowLong Lib "user32" Alias "SetWindowLongA" (ByVal hWnd _
As Long, ByVal nIndex As Long, ByVal dwNewLong As Long) As Long
Declare Function CallWindowProc Lib "user32" Alias "CallWindowProcA" (ByVal _
lpPrevWndFunc As Long, ByVal hWnd As Long, ByVal Msg As Long, ByVal wParam As _
Long, ByVal lParam As Long) As Long
 
Public Const WM_SYSCOMMAND = &H112
 
Private Declare Function CreatePopupMenu Lib "user32" () As Long
 
Private Const MF_STRING = &H0&
Private Const MF_SEPARATOR = &H800&
Private Const MF_MENUBARBREAK = &H20&
Private Const MF_POPUP = &H10&
Private Const MF_MENUBREAK = &H40&
Private Const MF_BYCOMMAND = &H0&
Private Const MF_GRAYED = &H1&
Private Const MF_DISABLED = &H2&
Private Const MF_CHECKED = &H8&
 
Const MENU_OPEN = 400
Const MENU_SAVE = 401
Const MENU_CHECKED = 402
Const MENU_DISABLED = 403
Const MENU_PRINT = 404
Const MENU_EXIT = 405
 
Public Const GWL_WNDPROC = (-4)
Public Const IDM_CUSTOM As Long = 1010
Public lProcOld As Long
 
Public Function SysMenuHandler(ByVal hWnd As Long, ByVal iMsg As Long, ByVal _
  wParam As Long, ByVal lParam As Long) As Long
 
    If iMsg = WM_SYSCOMMAND Then
        If wParam = MENU_OPEN Then
            MsgBox "VB Web About...", vbInformation, "About"
            Exit Function
        End If
    End If
    SysMenuHandler = CallWindowProc(lProcOld, hWnd, iMsg, wParam, lParam)
 
End Function
 
Public Function SubClass(FormName As Form, sMenu As String)
    Dim lhSysMenu As Long, lRet As Long, hSubMenu As Long
 
    hSubMenu = CreatePopupMenu()
    lhSysMenu = GetSystemMenu(FormName.hWnd, 0&)
 
    AppendMenu lhSysMenu, MF_SEPARATOR, 0&, vbNullString
    AppendMenu hSubMenu, MF_STRING, MENU_OPEN, "Open"
    AppendMenu hSubMenu, MF_STRING, MENU_SAVE, "Save"
    AppendMenu hSubMenu, MF_STRING Or MF_CHECKED, MENU_CHECKED, "Checked"
    AppendMenu hSubMenu, MF_STRING Or MF_GRAYED, MENU_DISABLED, "Disabled"
    AppendMenu hSubMenu, MF_STRING, MENU_PRINT, "Print"
    AppendMenu hSubMenu, MF_STRING, MENU_EXIT, "Exit"
    AppendMenu lhSysMenu, MF_STRING + MF_POPUP, hSubMenu, sMenu
 
    lProcOld = SetWindowLong(FormName.hWnd, GWL_WNDPROC, AddressOf _
      SysMenuHandler)
 
End Function